Devices with a high-mobility channel, such as Si, SiGe, Ge and compound semiconductors offer the possibility of increased device performance beyond traditional Si-based devices. In particular, Ge and Ge-containing materials are attractive candidates due to lower effective mass and higher mobility for charge carriers compared to Si. However, one of the issues with the high mobility channel is the poor oxide and interface quality that can result in device degradation.
HfO2-based dielectrics have successfully replace SiO2 in the state of art CMOS technology. However, in order to continue the further scaling of the HfO2-based gate dielectric and other high-k dielectrics, it is necessary to scale the equivalent oxide thickness (EOT) by scaling the overall dielectric thickness, including the thickness of the interface layer.